An X-ray diagnostic device, a magnetic resonance (MR) diagnostic device, and an ultrasonic diagnostic device are widely used as diagnostic imaging devices for examining bodies. In particular, the ultrasonic diagnostic device has advantages such as its non-invasive nature and real-time performance and is widely used for diagnostics including medical examinations. The ultrasonic diagnostic device is used in diagnostics for a variety of regions of the body including heart, liver, and a breast. One of the most important regions is the breast due to high morbidity and increased number of patients of breast cancers.
Hereinafter, a description is given of an example where a breast is examined. For ultrasonically examining a breast, imaging is performed while scanning an ultrasonic probe over the breast. Here, due to contact state between the ultrasonic probe and the breast or deformity of the breast, image degradation of the ultrasonic images or deformation of mammary tissue occurs. Therefore, ultrasonic images taken from one direction may not be sufficient for an accurate diagnosis.
In view of this, a method has been recently gaining attention where a three-dimensional tissue structure within the breast is constructed from temporally-different ultrasonic images obtained by scanning using a ultrasonic probe. The method increases diagnostic accuracy by observing the same region from different directions. For constructing the three-dimensional tissue structure, each ultrasonic image is mapped into the three-dimensional space based on the positional information of the ultrasonic image (position and orientation of the ultrasonic probe). The positional information is obtained from, for example, a camera, various types of sensors such as a magnetic sensor and an acceleration sensor, or a robotic arm.